Substrate processing apparatus, substrate processing method, and method of fabricating semiconductor device using the same

ABSTRACT

A substrate processing method includes providing a substrate into a process chamber; introducing a reference light into the process chamber; generating a plasma light in the process chamber while performing an etching process on the substrate; receiving the reference light and the plasma light; and detecting an etching end point by analyzing the plasma light and the reference light. Detecting the etching end point includes a compensation adjustment based on a change rate of an absorption signal of the reference light with respect to a change rate of an emission signal of the plasma light

CROSS-REFERENCE TO RELATED APPLICATION

This U.S. nonprovisional application claims priority under 35 U.S.C §119 to Korean Patent Application No. 10-2018-0145245, filed on Nov. 22,2018 in the Korean Intellectual Property Office, and the entire contentsof which are hereby incorporated by reference.

BACKGROUND

The present inventive concepts relate to an apparatus and method ofprocessing a substrate and a method of fabricating a semiconductordevice, and more particularly, to a substrate processing apparatus thatdetects an etching end point, a substrate processing method, and amethod of fabricating a semiconductor device using the same.

Semiconductor devices are fabricated using various semiconductormanufacturing processes such as deposition processes, ion implantationprocesses, photolithography processes, and etching processes. A plasmamay be used to perform some of the semiconductor manufacturingprocesses. As the semiconductor devices have become highly integrated,the structures of the semiconductor devices have been complicated. Inparticular, semiconductor devices having more complicated structureshave been recently developed. Accordingly, the semiconductormanufacturing processes are more complicated and thus increasedfabrication time is often required to fabricate semiconductor devices.

SUMMARY

Some example embodiments of the present inventive concepts provide asubstrate processing apparatus and method with improved detectabilityand reliability.

According to some example embodiments of the present inventive concepts,a substrate processing method may comprise: providing a substrate into aprocess chamber; introducing a reference light into the process chamber;generating a plasma light in the process chamber while performing anetching process on the substrate; receiving the reference light and theplasma light; and detecting an etching end point by analyzing the plasmalight and the reference light. The step of detecting the etching endpoint may include a compensation adjustment based on a change rate of anabsorption signal of the reference light with respect to a change rateof an emission signal of the plasma light.

According to some example embodiments of the present inventive concepts,a substrate processing method may comprise: providing a substrate into aprocess chamber; using a light source to introduce a reference lightinto the process chamber; using a radio frequency (RF) power supply toprovide a RF power to generate a plasma light in the process chamber;and monitoring a condition of the process chamber by receiving thereference light and the plasma light. The step of monitoring thecondition of the process chamber may comprise: obtaining an absorptionsignal of the reference light and an emission signal of the plasmalight; obtaining an emission signal of the plasma light; and obtainingthe absorption signal of the reference light by eliminating the emissionsignal of the plasma light from the absorption signal of the referencelight and the emission signal of the plasma light.

According to some example embodiments of the present inventive concepts,a method of fabricating a semiconductor device may comprise: providing aprocess chamber with the semiconductor device including an etchingtarget layer; performing an etching process on the semiconductor device;monitoring a condition of the process chamber to detect an etching endpoint; and after detecting the etching end point, terminating theetching process and then performing a subsequent process on thesemiconductor device. The step of performing the etching process maycomprise: using a light source to introduce a reference light into theprocess chamber; and using a radio frequency (RF) power supply toprovide a RF power to generate a plasma light in the process chamber.The step of detecting the etching end point may comprise: analyzing theplasma light to obtain an emission signal of the plasma light; analyzingthe reference light to obtain an absorption signal of the referencelight; and compensating for the detection of the etching end point byconsidering the absorption signal of the reference light with respect tothe emission signal of the plasma light.

According to some example embodiments of the present inventive concepts,a substrate processing apparatus may comprise: a process chamberincluding first and second viewports facing each other; a light sourceadjacent to the first viewport and providing the process chamber with areference light; a radio frequency (RF) power supply providing a RFpower to generate a plasma light in the process chamber; alight-receiving part adjacent to the second viewport and arranged toreceive the reference light and the plasma light; an analyzer receivingthe reference light and the plasma light from the light-receiving partand configured to analyze the reference light and the plasma light; anda polarizing filter adjacent to the light-receiving part and filteringat least a portion having a transverse electric wave (TE) mode of alight received on the second viewport.

Details of other example embodiments are included in the description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic diagram showing a substrate processingapparatus according to some example embodiments of the present inventiveconcepts.

FIG. 2A illustrates a flow chart showing a method of fabricating asemiconductor device according to some example embodiments of thepresent inventive concepts.

FIG. 2B illustrates a detailed flow chart showing a step of performingan etching process and a step of monitoring a condition of a processchamber and detecting an etching end point shown in the flow chart ofFIG. 2A.

FIGS. 3A to 3G illustrate a method of fabricating a semiconductor devicesuch as shown in FIGS. 2A and 2B.

FIG. 4 illustrates a graph showing a plasma intensity according to someexample embodiments of the present inventive concepts.

DETAILED DESCRIPTION OF EMBODIMENTS

Some example embodiments of the present inventive concepts will bedescribed below in detail with reference to the accompanying drawings.

FIG. 1 illustrates a schematic diagram showing a substrate processingapparatus 1 according to some example embodiments of the presentinventive concepts. The substrate processing apparatus 1 may use, forexample, a plasma to etch a substrate S. The substrate S may be asemiconductor substrate for fabricating a semiconductor device, such asfor fabricating a plurality of integrated circuits on a wafer that formsemiconductor chips when singulated from the wafer, or may be a glasssubstrate for manufacturing a flat display device, but the presentinventive concepts are not limited thereto.

The substrate processing apparatus 1 may be a capacitively coupledplasma processing apparatus, but alternatively may be an inductivelycoupled plasma processing apparatus, a microwave plasma processingapparatus, or any other type of plasma processing apparatus. Thefollowing will describe an example in which the substrate processingapparatus 1 is a capacitively coupled plasma processing apparatus. Toeffectively perform plasma processing processes, it may be important toinspect an internal condition of a process chamber and to check a plasmacondition (electron density, ion density, etc.)

The substrate processing apparatus 1 may include a process chamber 100,a radio frequency (RF) power supply 200, a matcher 300, a light source420, a light-receiving part OF, an analysis part 440, and a controller500.

The process chamber 100 may have an internal space 101 where thesubstrate W is processed. A plasma (see P of FIG. 3C) may be generatedin the internal space 101, in which the substrate S is processed by theplasma. The process chamber 100 may have a hermetic structure tomaintain a vacuum state. The process chamber 100 may include one or moreof metal and dielectric materials. Although not shown, the processchamber 100 may include upper and lower chamber portions combined witheach other, and may have a hollow hexahedral shape, a hollow cylindricalshape, or any other shapes.

The process chamber 100 may include first, second, third, and fourthwalls 102, 104, 106, and 108. The first wall 102 may be an upper wall,and the third wall 106 may be a lower wall facing the first wall 102.The second wall 104 may be a lateral wall, and the fourth wall 108 maybe an opposite lateral wall facing the second wall 104.

The process chamber 100 may include viewports 110 a and 110 b, ashowerhead 120, and a stage 130.

The viewports 110 a and 110 b may be provided on the process chamber100. A first viewport 110 a may be installed on a lateral wall of theprocess chamber 100, and a second viewport 110 b may be installed on anopposite lateral wall facing the lateral wall. For example, the firstviewport 110 a may be disposed on the fourth wall 108 of the processchamber 100, and the second viewport 110 b may be disposed on the secondwall 104. Ordinal numbers such as “first,” “second,” “third,” etc. maybe used simply as labels of certain elements, steps, etc., todistinguish such elements, steps, etc. from one another. Terms that arenot described using “first,” “second,” etc., in the specification, maystill be referred to as “first” or “second” in a claim. In addition, aterm that is referenced with a particular ordinal number (e.g., “third”in a particular claim) may be described elsewhere with a differentordinal number (e.g., “first” in the specification or another claim).

The viewports 110 a and 110 b may be made of glass, quartz, or othermaterials transparent to light. The viewports 110 a and 110 b may betransparent to infrared rays, ultraviolet rays, or visible light bands.The viewports 110 a and 110 b may be provided in openings that arehermetically sealed to allow the process chamber 100 to maintain avacuum state without introduction of impurities.

The viewports 110 a and 110 b are not limited to being disposed on thelateral walls of the process chamber 100, but may be disposed on anupper wall of the process chamber 100 or on a gas exhaustion part (notshown) of the process chamber 100. The viewports 110 a and 110 b may beanti-reflectively coated, and may have their transmittance that isconstant irrespective of wavelength. FIG. 1 shows two viewports 110 aand 110 b facing each other, but the number and arrangement of theviewports 110 a and 110 b may not be limited thereto. The viewports 110a and 110 b may further be provided with deposition shields. In oneembodiment, the viewports 110 a and 110 b may form the lateral walls ofthe process chamber 100, so that the walls of the process chamber 100include the viewports. For example, the second wall 104 and fourth wall108 may be formed in part by a chamber housing material or materials(e.g., metal and dielectric materials) and in part by a viewport formed,for example, of a transparent material (e.g., glass, quartz, etc.).

Although not shown, the process chamber 100 may further include a gassupply port and a gas exhaustion port. A process gas for processing asemiconductor device may be supplied through the gas supply port (notshown), and a non-reacted source gas and byproducts of semiconductordevice processes may be drained through the gas exhaustion port (notshown). The process gas may include, for example, one or more of CF₄,C₄F₆, C₄F₈, COS, CHF₃, HBr, SiCl₄, O₂, N₂, H₂, NF₃, SF₆, He, Xe, and Ar.The present inventive concepts, however, are not limited thereto.

The showerhead 120 may be placed in the internal space 101 of theprocess chamber 100. The showerhead 120 may be installed in an innerupper portion of the process chamber 100. The showerhead 120 may supplythe process gas into the process chamber 100. The showerhead 120 mayuniformly spray the process gas onto substrate S. The showerhead 120 mayserve as a top electrode. The showerhead 120 may be connected to areference potential. For example, while a plasma etching process isperformed, the showerhead 120 may be grounded (G) or alternativelyconnected to a radio frequency (RF) power. Hereinafter, the showerhead120 may also be called a top electrode.

The stage 130 may be provided in the internal space 101 of the processchamber 100, thereby supporting a semiconductor device. The substrate Smay be loaded on a top surface of the stage 130. The stage 130 may beinstalled in an inner bottom side of the process chamber 100. The stage130 may be disposed to face the showerhead 120. The stage 130 may serveas a bottom electrode into which a plurality of RF powers are suppliedfrom the RF power supply 200. The stage 130 may be shaped like a flatplate. For example, the stage 130 may be equipped with an electrostaticchuck that uses an electrostatic power to rigidly place a semiconductordevice, such as a semiconductor wafer, thereon. The stage 130 mayinclude a heater that heats a semiconductor device to a temperaturesuitable for plasma treatment. For example, the heater may be providedin the form of a hot wire embedded in the stage 130. Hereinafter, thestage 130 may also be called a bottom electrode. The stage 130 may haveon its top surface a confinement ring 140 provided outside the substrateS.

The RF power supply 200 may be provided to supply the bottom electrode130 with a radio frequency (RF) power for plasma generation or plasmacontrol. The RF power supply 200 may be provided as a single powergenerator or a plurality of power generators. For example, the RF powersupply 200 may include a first RF power generator 220 and a second RFpower generator 240. Optionally, the RF power supply 200 may apply a RFpower not only to the bottom electrode 130 but also to any othercomponent. For example, the RF power supply 200 may apply a RF power tothe top electrode 120.

The first RF power generator 220 may supply a first RF power having afirst frequency. The first RF power generator 220 may be a source RFpower supply that applies a source RF power, and the first RF power maygenerate a plasma in the process chamber 100. For example, when thefirst RF power is applied to the bottom electrode 130, the plasma may begenerated from a process gas introduced into the process chamber 100.Alternatively, there may be provided a plurality of first RF powergenerators 220 each of which applies a source RF power.

The second RF power generator 240 may supply a second RF power having asecond frequency. The second frequency may be lower than the firstfrequency. The second RF power generator 240 may be a bias RF powersupply, and the second RF power may cause cations to travel onto thesubstrate S. In this description, the first and second frequencies maybe a radio frequency (RF).

When the RF power supply 200 applies a radio frequency energy to theprocess chamber 100, the bottom electrode 130 and the top electrode 120may have therebetween an electric field caused by a difference inelectrical potential therebetween, with the result that a plasma may begenerated in the process chamber 100. A density of the plasma generatedon the substrate S may be changed depending on a difference in potentialbetween the bottom electrode 130 and the top electrode 120. The radiofrequency of the RF power supply 200 may be controlled to adjustconditions of the plasma in the process chamber 100.

The matcher 300 may be an RF match circuit installed between the RFpower supply 200 and the process chamber 100. The matcher 300 may reduceor minimize loss of the RF powers generated from the RF power supply200. It therefore may be used to obtain an increased transfer efficiencyof the RF powers provided from the RF power supply 200 to the bottomelectrode 130. The matcher 300 may be provided in plural to correspondto the number of the RF power generators 220 and 240, and the pluralityof matchers 300 may be connected to corresponding RF power generators220 and 240. The plurality of matchers are omitted for brevity ofillustration.

The light source 420 may be disposed adjacent to the first viewport 110a. The light source 420 may be driven at low power (e.g., 1 mW or less),and thus may have no effect on a chemical reaction (e.g., excitement ordissociation) of the plasma. The light source 420 may be, for example, alamp including xenon (Xe). The light source 420 and the first viewport110 a may be provided with a first collimator 422 therebetween outsidethe first viewport 110 a. The first collimator 422 may be a collimatorlens, but the present inventive concepts are not limited thereto. Thefirst collimator 422 may collimate a reference light (see RL of FIG. 3C)released from the light source 420 (e.g., a light beam generated andoutput from the light source 420). Although not shown, an optical fibercable may be provided between the light source 420 and the firstcollimator 422.

The light-receiving part OF may be disposed adjacent to the secondviewport 110 b. The light-receiving part OF may be, for example, anoptical fiber. The light-receiving part OF may receive the referencelight RL emitted from the light source 420 and a plasma light PLgenerated from a plasma P (see FIG. 3C). In this description, forclarity of description, the reference light RL emitted from the lightsource 420 is explained independently of the plasma light PL generatedfrom the plasma P.

The light-receiving part OF and the second viewport 110 b may beprovided with a second collimator 432 therebetween, formed outside thesecond viewport 110 b. The second collimator 432 may be a collimatorlens, but the present inventive concepts are not limited thereto. Thesecond collimator 432 may collimate light that is received from insidethe chamber 100 and transmitted toward the light-receiving part OF.

A filter 430 may be provided between the second collimator 432 and thesecond viewport 110 b. The filter 430 may filter at least a portion ofthe light received from inside the chamber 100 and transmitted towardthe light-receiving part OF. The filter 430 may filter a polarizedcomponent of the light received from inside the chamber 100. Forexample, the filter 430 may filter at least a portion having atransverse electric wave (TE) mode of the light received from inside thechamber 100 at the filter 430, such that this portion is not transmittedto the light-receiving part OF. The filtering of the TE mode componentmay eliminate a noise component produced in the process chamber 100, forexample, amplified noise caused by reflection between the showerhead 120and the substrate S. The light-receiving part OF may transfer thereceived light (e.g., the filtered, collimated light) to the analysispart 440.

The analysis part 440 may be an analyzer and include equipment such as aspectrometer. For example, the analysis part 400, such as aspectrometer, may include measurement components, as well as hardwareand software components configured to perform measurement and analysistasks such as those described herein. The analysis part 440 may useoptical emission spectroscopy (OES) mode and optical absorptionspectroscopy (OAS). The analysis part 440 may convert the referencelight RL and the plasma light PL into electrical signals, and analyzethe converted electrical signals. For example, the analysis part 440 mayreceive the plasma light PL to analyze an emission signal of the plasmalight PL, and also receive the reference light RL and the plasma lightPL to analyze an absorption signal of the reference light RL. Throughthe process above, it is possible to monitor a condition of the processchamber 100. The analysis part 440 may include a display (not shown) aswell as other user input-output devices for user control.

The controller 500 may control the showerhead 120, the stage 130, the RFpower supply 200, the matcher 300, the light source 420, thelight-receiving part OF, and the analysis part 440. For example, thecontroller 500 may control and synchronize the RF power supply 200, thelight source 420, the light-receiving part OF, and the analysis part440. For example, the controller 500 may include control components suchas hardware and software components configured to perform controlfunctions such as those described herein. A detailed description will begiven below with reference to the accompanying drawings.

FIG. 2A illustrates a flow chart showing a method of fabricating asemiconductor device according to some example embodiments of thepresent inventive concepts. FIG. 2B illustrates a detailed flow chartshowing a step S200 of performing an etching process and a step S300 ofmonitoring a condition of the process chamber and detecting an etchingend point shown in the flow chart of FIG. 2A. Thus, FIGS. 2A and 2Billustrate one example embodiment. FIGS. 3A to 3G illustrate a method offabricating a semiconductor device shown in FIGS. 2A and 2B. Thefollowing will describe a method of fabricating a semiconductor deviceaccording to some example embodiments of the present inventive conceptswith reference to FIGS. 2A to 3G.

Referring to FIG. 2A, the substrate S may be loaded on the processchamber 100 (S100). The substrate S may be received on the stage 130.Although not shown, an elevation member (e.g., a robot arm) or the likemay be provided to load the substrate S. The substrate S may be asemiconductor substrate for fabricating a semiconductor device, or aglass substrate for manufacturing a flat display device, but the presentinventive concepts are not limited thereto.

Referring to FIG. 3A, the substrate S may include a semiconductor layer10, a pattern 20, an anti-reflection layer 22, and an etching targetlayer 30. The semiconductor layer 10 may be a silicon substrate, agermanium substrate, or a silicon-germanium substrate. The pattern 20may be formed on the semiconductor layer 10, and the anti-reflectionlayer 22 and the etching target layer 30 may be formed on the pattern20. Except for the etching target layer 30, the semiconductor layer 10,the pattern 20, and the anti-reflection layer 22 may be non-etchingtarget layers.

The etching target layer 30 may be composed of a semiconductor material,a conductive material, a dielectric material, or a combination thereof.For example, when the etching target layer 30 is composed of asemiconductor material, the etching target layer 30 may include the samesemiconductor material as that of the semiconductor substrate and/orthat of an epitaxial layer. Alternatively, the etching target layer 30may include a conductive material such as doped polysilicon, metalsilicide, metal, metal nitride, or a combination thereof When theetching target layer 30 is composed of a dielectric material, theetching target layer 30 may include a dielectric material such siliconoxide, silicon nitride, silicon oxynitride, low-k dielectric whosedielectric constant is less than that of silicon oxide, or a combinationthereof. Alternatively, the etching target layer 30 may includecrystalline silicon, amorphous silicon, impurity doped silicon,silicon-germanium, carbon-based material, or a combination thereof FIG.3A shows the etching target layer 30 is composed of a single layer, butalternatively the etching target layer 30 may be formed of a pluralityof stacked layers. For example, the etching target layer 30 may includea plurality of stacked dielectric layers and further include at leastone conductive or semiconductor layer between the dielectric layers.

Referring to FIGS. 2A and 2B, a plasma is generated in the processchamber 100 to perform an etching process (S200). The etching processincludes introducing a reference light into the process chamber 100(S210) and generating the plasma (S220). The introduction of thereference light into the process chamber 100 (S210) may be performedsimultaneously with the generation of the plasma (S220).

Referring to FIGS. 2A, 2B, and 3C to 3G, a step may be performed tomonitor a condition of the process chamber 100 and to detect an etchingend point (S300). The step of monitoring the condition of the processchamber 100 and detecting the etching end point (S300) may includeanalyzing a plasma light and the reference light (S310), detecting theetching end point (S320), and compensating for the detection of theetching end point (S330).

For example, referring to FIG. 3B, the controller 500 may control ON/OFFstates of each of the light source 420, the analysis part 440, and theRF power supply 200. FIG. 3B shows an example in which the controller500 controls a Xenon lamp as the light source 420, a spectrometer as theanalysis part 440, and the first RF power generator 220 as the source RFpower generator.

The controller 500 may synchronize and simultaneously turn on the lightsource 420, the spectrometer 440, and the first RF power generator 220.The light source 420 and the RF power may be supplied in a pulsed mode.In the figures, time durations are shown for brevity of illustration,and may be different from actual period of times. For example, an ON/OFFperiod of the light source 420 may correspond to several seconds [s],but an ON/OFF period of the first RF power generator 220 may correspondto several milliseconds [ms]. The ON/OFF period of the first RF powergenerator 220 may be relatively shorter, and may have a frequency suchthat the plasma-producing effect can be controlled to be similar to thatwhich occurs when the first RF power generator 220 is always in an ONstate.

Based on a first duration or time period (e.g., duration (A) of FIG. 3B)in which the light source 420 is in an ON state and a second duration(or duration (B) of FIG. 3B) in which the light source 420 is an OFFstate, the controller 500 may analyze the plasma light PL and thereference light RL (S310). FIG. 3C illustrates a schematic diagramcorresponding to the first duration (A), and FIG. 3D illustrates aschematic diagram corresponding to the second duration (B).

Referring to FIGS. 3B and 3C, in the first duration (A), the lightsource 420 supplies the process chamber 100 with the reference light RL,and the plasma light PL is generated from the plasma P. In the firstduration (A), the light-receiving part OF receives the reference lightRL and the plasma light PL at the same time. In this case, it ispossible to obtain an absorption signal from the reference light RL andalso to obtain an emission signal of the plasma light PL. In thisdescription, it is assumed that the reference light RL has no effect onthe emission signal, or on the optical emission spectroscopy (OES). Incontrast, the plasma light PL may have an effect on the emission signaland the absorption signal.

Referring to FIGS. 3B and 3D, in the second duration or time period(e.g., B), the light source 420 is in an OFF state, and thus only theplasma light PL is generated from the plasma P. In the second duration(B), the light-receiving part OF receives only the plasma light PL. Inthis case, it may be possible to obtain the emission signal of theplasma light PL.

The controller 500 is configured to use the absorption and emissionsignals obtained from the plasma light PL in the second duration (B) toextract only the absorption signal of the reference light RL, therebycompensating for the light generated by the plasma. For example, thecontroller 500 may extract only the absorption signal of the referencelight RL by eliminating the absorption and emission signals of theplasma light PL obtained in the second duration (B) from the absorptionsignal of the reference light RL and the emission signal of the plasmalight PL obtained in the first duration (A). Also, the controller 500may use data of the first and second durations (A) and (B) to detect theemission signal of the plasma light PL and the absorption signal of thereference light RL.

Referring to FIG. 3E, it may be possible to ascertain an intensity ofthe emission signal of the plasma light PL. In this case, it may bedifficult to detect an etching end point. The etching end point may berecognized when the intensity of the emission signal of the plasma lightPL is greatly changed at the moment that the etching target layer (see30 of FIG. 3A) is etched to expose the non-etching target layer (e.g.,the reference numeral 22 of FIG. 3A). However, referring to FIG. 3E, itmay be hard to detect a point where the intensity of the emission signalof the plasma light PL is abruptly changed.

Referring to FIG. 3F, it may be possible to ascertain an intensity ofthe absorption signal of the reference light RL. The reference light RLmay be provided at lower power to minimally affect a chemical reactioninside the process chamber 100. However, it may be seen that thereference light RL decreases in output intensity and therefore increasesthe magnitude of the absorption signal as the time goes by, and thus itmay be found that external factors reduce the output intensity andtherefore increase the magnitude of the absorption signal of thereference light RL. A pollution level of the process chamber 100 may bedetected by real-time monitoring the absorption signal of the referencelight RL. For example, it may be possible to detect contamination of aninner surface 110 i of the process chamber 100 or the viewports 110 aand 110 b. Accordingly, the viewports 110 a and 110 b or any othercomponents may be replaced if needed.

For example, the reduction in intensity of the reference light RL asindicated by an increase in magnitude of the absorption signal of thereference light RL may be used to ascertain the pollution level insidethe process chamber 100, and this may be used to estimate an influenceon an intensity of a reflection signal of the plasma light PL.

According to aspects of the present inventive concepts, the etching endpoint may be detected and compensated for (e.g., an inaccuratedetermination of the etching end point due to changes in the plasmachamber, such as additional contaminants, may be corrected) byconsidering a change rate of the absorption signal of the referencelight RL with respect to a change rate of the emission signal of theplasma light PL (S320 and S330). For example, an error of the etchingend point may be compensated for (e.g., by performing a compensationadjustment) by dividing the change rate of the emission signal of theplasma light PL by the change rate of the absorption signal of thereference light RL. The change rate of the emission signal of the plasmalight PL may be obtained from the emission signal of the plasma light PLat a certain time (e.g., by detecting a series of emission measurementsover a period of time and determining the rate of change at a given timebased on an overall emission-versus-time curve), and the change rate ofthe absorption signal of the reference light RL may be obtained from theabsorption signal of the reference light RL at a certain time (e.g., bydetecting a series of absorption measurements over a period of time anddetermining the rate of change at a given time based on an overallabsorption-versus-time curve). For example, when the change rate of theemission signal is divided by the change rate of the absorption signalfor a series of time points, the resulting values may form acharacteristic graph that includes a clear change point (also describedas a signal edge point, or a signal jump) where a graph curve abruptlychanges. The time point at which one of these change points occurs maycorrespond to an etching end point. Therefore, it may be possible tocompensate for an error caused by internal contamination. The detectionand error compensation for the etching end point (S320 and S330) may beperformed at the same time, but the present inventive concepts are notlimited thereto. The etching end point may be referred to as an etchingcompletion point.

FIG. 3G shows a graph that compares an emission signal pOES of a plasmalight according to comparative examples with an emission signal cOES ofa plasma light that is compensated for according to some exampleembodiments of the present inventive concepts. The emission signal pOESof the plasma light of the comparative example may be the same as dataof FIG. 3E. The compensated emission signal cOES of the plasma light maybe used to more easily detect an etching end point EP by compensatingfor detection errors caused by internal contamination, as discussedabove. Accordingly, reliability may improve and detectability mayincrease. In FIG. 3G, the etching end point EP may correspond to a timepoint at which the graph of cOES is abruptly bent near to its end point.

Referring to FIG. 2A, when the etching end point is ascertained, theetching process may be terminated (S400), and then subsequent processesmay be performed on the substrate S (S500). Because the etching endpoint indicates that the non-etching target layer (e.g., the referencenumeral 22 of FIG. 3A) is exposed, after the etching end point isascertained, the etching process may be promptly terminated. Thesubsequent processes may be, but are not limited to, a cleaning processand any other processes for fabricating various layers, patterns, andcomponents of a semiconductor device to form an integrated circuit on adie, that can be singulated into chips, and formed into semiconductorpackages. If needed, the substrate S may undergo the subsequentprocesses in the same process chamber 100, or may be unloaded from theprocess chamber 100 and then loaded in other process chamber.

According to the present inventive concepts, a substrate processingapparatus and method may be provided that have improved detectabilityand reliability.

FIG. 4 illustrates a graph showing a plasma intensity according to someexample embodiments of the present inventive concepts. The controller500 may detect a specific time AP that an arcing occurs when theabsorption signal of the reference light RL is monitored by connectingan optical sensor (e.g., Fast-Time OES) to the light-receiving part OFand the analysis part 440. In a case where a component analysis isperformed at the specific time AP, the optical sensor may be used tofind a certain component (e.g., showerhead) at which the arcing occurs.

According to some example embodiments of the present inventive concepts,it may be possible to provide substrate processing apparatus and methodwith improved detectability and reliability.

The effects of the present inventive concepts are not limited to theaforementioned effects. Other effects, which are not mentioned above,will be apparently understood by one skilled in the art from theforegoing description and accompanying drawings.

These embodiments herein are presented to facilitate understanding ofthe present inventive concepts and should not limit the scope of thepresent inventive concepts, and it is intended that the presentinventive concepts cover the various combinations, the modifications,and variations. The technical protection scope of the present inventiveconcepts will be defined by the technical spirit of the appended claims,and is intended to include all modifications and equivalentsubstantially falling within the spirit and scope of the invention whilenot being limited by literary descriptions in the appended claims.

1. A substrate processing method, comprising: providing a substrate intoa process chamber; introducing a reference light into the processchamber; generating a plasma light in the process chamber whileperforming an etching process on the substrate; receiving the referencelight and the plasma light; and detecting an etching end point byanalyzing the plasma light and the reference light, wherein detectingthe etching end point includes a compensation adjustment based on achange rate of an absorption signal of the reference light with respectto a change rate of an emission signal of the plasma light.
 2. Thesubstrate processing method of claim 1, wherein analyzing the plasmalight comprises obtaining the change rate of the emission signal of theplasma light, analyzing the reference light comprises obtaining thechange rate of the absorption signal of the reference light, anddetecting the etching end point comprises obtaining a compensatedemission signal of the plasma light by dividing the change rate of theemission signal of the plasma light by the change rate of the absorptionsignal of the reference light.
 3. The substrate processing method ofclaim 1, wherein the reference light is introduced by a light source,and the plasma light is introduced by supplying a radio frequency (RF)power generated from a RF power supply, and the light source and the RFpower supply are synchronized such that introducing the reference lightis simultaneously performed with generating the plasma light.
 4. Thesubstrate processing method of claim 3, wherein the light source and theRF power supply are ON/OFF switched in a pulsed mode, wherein receivingthe reference light and the plasma light comprises: a first duration inwhich the reference light and the plasma light are received; and asecond duration in which the plasma light is selectively receivedwithout the reference light.
 5. The substrate processing method of claim4, wherein receiving the reference light and the plasma light comprises:in the first duration, obtaining an absorption signal of the referencelight and an emission signal of the plasma light; and in the secondduration, obtaining absorption and emission signals of the plasma light.6. The substrate processing method of claim 5, wherein the compensationadjustment comprises obtaining the absorption signal of the referencelight by eliminating the emission signal of the plasma light obtained inthe second duration from the absorption signal of the reference lightand the emission signal of the plasma light obtained in the firstduration.
 7. The substrate processing method of claim 1, whereinreceiving the reference light and the plasma light comprises filteringand receiving at least a portion having a transverse electric wave (TE)mode of the reference light and the plasma light.
 8. The substrateprocessing method of claim 1, further comprising receiving the referencelight and the plasma light to monitor a condition of the processchamber.
 9. The substrate processing method of claim 8, whereinmonitoring the condition of the process chamber comprises monitoring apollution level of an inner surface of the process chamber.
 10. Thesubstrate processing method of claim 8, wherein monitoring the conditionof the process chamber comprises using the absorption signal of thereference light to analyze a component at which an arcing occurs in theprocess chamber.
 11. The substrate processing method of claim 1, whereinintroducing the reference light into the process chamber comprisesproviding the reference light to a first viewport on a sidewall of theprocess chamber, wherein the provided reference light is collimated by afirst collimator adjacent to the first viewport.
 12. The substrateprocessing method of claim 11, wherein receiving the reference light andthe plasma light comprises providing the reference light and the plasmalight to a second viewport disposed to face the sidewall of the processchamber, wherein the provided reference light and plasma light arecollimated by a second collimator adjacent to the second viewport.
 13. Asubstrate processing method, comprising: providing a substrate into aprocess chamber; using a light source to introduce a reference lightinto the process chamber; using a radio frequency (RF) power supply toprovide a RF power to generate a plasma light in the process chamber;and monitoring a condition of the process chamber by receiving thereference light and the plasma light, wherein monitoring the conditionof the process chamber comprises: obtaining an absorption signal of thereference light and an emission signal of the plasma light; obtainingabsorption and emission signals of the plasma light; and obtaining theabsorption signal of the reference light by eliminating the absorptionand emission signals of the plasma light from the absorption signal ofthe reference light and the emission signal of the plasma light.
 14. Thesubstrate processing method of claim 13, wherein monitoring thecondition of the process chamber comprises monitoring a pollution levelof an inner surface of the process chamber.
 15. The substrate processingmethod of claim 13, wherein monitoring the condition of the processchamber comprises using the absorption signal of the reference light toanalyze a component at which an arcing occurs in the process chamber.16. The substrate processing method of claim 13, wherein the lightsource and the RF power supply are synchronized to switch into an ONstate at the same time.
 17. The substrate processing method of claim 16,wherein the light source and the RF power supply are switched in apulsed mode, wherein receiving the reference light and the plasma lightcomprises: a first duration in which are obtained the absorption signalof the reference light and the emission signal of the plasma light; anda second duration in which are obtained the absorption and emissionsignals of the plasma light.
 18. The substrate processing method ofclaim 13, further comprising detecting an etching end point by analyzingthe reference light and the plasma light, wherein detecting the etchingend point comprises: obtaining a change rate of the emission signal ofthe plasma light; obtaining a change rate of the absorption signal ofthe reference light; and compensating for the detection of the etchingend point by considering the change rate of the absorption signal of thereference light with respect to the change rate of the emission signalof the plasma light.
 19. The substrate processing method of claim 18,wherein compensating for the detection of the etching end pointcomprises obtaining a compensated emission signal of the plasma light bydividing the change rate of the emission signal of the plasma light bythe change rate of the absorption signal of the reference light.
 20. Thesubstrate processing method of claim 13, wherein receiving the referencelight and the plasma light comprises filtering and receiving at least aportion having a transverse electric wave (TE) mode of the referencelight and the plasma light. 21-34. (canceled)